1. Field of the Invention
The present invention relates generally to an image recording apparatus by using a photosensitive recording medium, and more particularly to such an image recording apparatus which has upper and lower sections that are separable from each other for easy handling of a recording medium.
2. Discussion of the Prior Art
An example of an image recording apparatus is illustrated in FIG. 11, wherein a light source device 130 is disposed in an upper part of an upper section of the apparatus. Right below the light source device 130, there are disposed a color separation filter 140, and a transparent original 141 which bears an original image to be reproduced. The filter 140 has three filter elements corresponding to three primary colors of light, i.e., blue, green and red. Below the original 141 is a focusing lens 142 for focusing an image radiation transmitted through the original 141, on the surface of an active portion of a pressure-sensitive photosensitive web 123, which portion extends below the focusing lens 142. The photosensitive web 123 is supplied from a supply roll 122 which is accommodated in a suitable cassette mounted in a lower section of the apparatus. To the left of the supply roll 122 of the photosensitive web 123, there is disposed a take-up roll 124 on which a used length of the web 123 is wound. Above the take-up roll 124 is provided a developing device which includes a pair of presser rolls 126, and a pair of fixing rolls 127 which are located to the left of the presser rolls 126. Above the developing device is a sheet cassette 131 which stores a stack of developer sheets 132. Adjacent to an sheet outlet end of the sheet cassette 131 is provided a feed roller 133 for delivering the developer sheets 132 from the cassette 131.
In operation, the original 141 is irradiated by a radiation which is generated by the light source device 130 and which is transmitted through the color separation filter 140. The radiation which has passed the original 141 is focused by the focusing lens 142, on the surface of the active portion of the photosensitive web 123, whereby the active portion is imagewise exposed to the image radiation from the original 141, which represents the original image on the original 141. Thus, a latent image corresponding to the original image is formed on the photosensitive web 123. After the relevant portion of the web 123 is imagewise exposed, the developer sheet 132 is delivered from the sheet cassette 131, by the feed roller 133, and is superposed on the exposed length of the photosensitive web 123, before they are passed through a pressure nip between the presser rolls 126. With the passage of the exposed portion of the web 123 through the pressure nip of the presser rolls 126, together with the developer sheet 132, the latent image on the web 123 is developed into a visible image on the developer sheet 132. Then, the developer sheet 132 is passed through the nip of the fixing rolls 127, so that the visible image is fixed with enhanced color quality.
In the known image recording apparatus described above wherein the cassette for the photosensitive roll 122 is located in the lower section of the apparatus, it is considerably difficult to newly install or replace the roll 122. The installation or replacement of the cassette involves threading of the photosensitive web through the apparatus. To facilitate the installation or replacement of the photosensitive roll 122, it may be considered to divide the apparatus into upper and lower sections at an exposing path through which the photosensitive web 123 is fed, so that the upper and lower sections are separated from each other. However, a problem arises due to the location of the cassette for the photosensitive roll 122. Namely, the cassette occupies a substantial portion of the lower section of the apparatus, and therefore comparatively heavy devices and components should be disposed in the upper section of the apparatus. This may cause reduced installation and maintenance stability of the apparatus, particularly when the upper section is separated or removed from the lower base section.